When an image needs to be adjusted for brightness or color the usual
procedure is to open it in an image manipulation package such as Photoshop,
make the adjustments and save it to a new file. This procedure is tried and
true but it is unnecessarily cumbersome. What are shown below are some
Java applets which allow adjustment of the way an image is viewed through
simple modification of <param> tags. These applets allow quicker
viewing of how the adjustments appear than the open-modify-save-upload
sequence.

Suppose someone wants the farm scene below to appear a bit greener than
it is in reality.

The applet allows an increment in the green component of the color at each
pixel. Below is shown the result of adding 40 to the green component at
each pixel.

An alternate means would be to scale up the green component of the pixels
by some factor, say 1.5. The result is shown below:

The second method is better for maintaining contrasts.

Suppose a realistic image of blue roses is desired. One way to get
blue roses is to switch the blue and red component in the image. What
results has the subtle variations in color of a real rose but with
predominant blue color rather than red. The original and the result
are shown below.

If one wants an image of a yellow rose one can take a picture of a
yellow rose and scan it and upload it. Or, one can use the applet
and make the green component equal to the red component with the result
shown below:

Another version allows color modification within a selected area of the
image, as is illustrated below:

A variation on this is to modify the color everywhere except within a
selected area. In the case below the image outside of the selected area is
converted to gray-scale by making the RGB values for each pixel outside the
selected area equal to the average of the original values.

One version of the image manipulation applet makes provision for cropping the image and
for scaling the size of the image up or down:

The image manipulation applet computes the RGB values as a linear
transformation of the RGB values of the original image. One can invert
the colors by setting the

new values = 255 - original values.

This changes white to black and black to white. Each color is changed to its
complement; i.e., red becomes cyan, green become magenta, blue becomes yellow,
and vice versa.

Another feature implemented in a separate applet allows one image to
be imposed upon another with a specified degree of translucency (alpha value)
for each color component. An example is shown below:

Another entirely different applet allows for the conversion of a specific
color into another specified color as is shown below: